select con.SOG_ID 
from v_contratto con
where con.SER_ID =1
and con.az_id = '01'
  and con.STA_IDSYS = 2
  and con.VER_DTINI < '01-lug-2010'
intersect
select con.SOG_ID 
from v_contratto con
where con.SER_ID =3
and con.az_id = '01'
  and con.STA_IDSYS = 2
  and con.VER_DTINI < '01-lug-2010'